Nimodipine rescues N-methyl-N-nitrosourea-induced retinal degeneration in rats
Dan Wang1, Yan Li2, Zhuo Wang3, Gui-yuan Sun4, Qiu-hua Zhang5
1 Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Liaoning Shenyang; Department of Pharmacology, HE's University, Liaoning Shenyang, China
2 Department of Physiology, Experimental Teaching Center of Pharmacology, School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Liaoning Shenyang, China
3 Department of Pharmacology, HE's University, Liaoning Shenyang, China
4 Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Liaoning Shenyang, China
5 Department of Basic Pharmacology, Liaoning University of Traditional Chinese Medicine, Liaoning Shenyang, China
|Date of Submission||14-Feb-2012|
|Date of Decision||29-Feb-2012|
|Date of Web Publication||30-Apr-2013|
Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Liaoning Shenyang
Source of Support: China Medical University., Conflict of Interest: None
| Abstract|| |
Background: That nimodipine (NMD) is potentially useful for ophthalmic treatment. However, the effect of NMD is unknown on retinal degenerative diseases. Objective: The purpose of the present study was to investigate the effect of NMD on N-methyl-N-nitrosourea (MNU)-induced retinal degeneration (RD) and elucidate its possible mechanisms. Materials and Methods: Morphological observation of NMD on MNU-induced RD was evaluated by light microscopy and electron microscopy. Nonenzymatic antioxidant glutathione (GSH) was measured by a colorimetric method. Transforming growth factor-beta (TGF-β) was measured by enzyme-linked immunosorbent assay (ELISA). Telomerase was detected by reverse transcriptase polymerase chain reaction (RT-PCR). Results: The significantly protective effect of NMD on MNU-induced RD was demonstrated morphologically. NMD increased the content of GSH and decreased the level of TGF-β in rat retina. RT-PCR analysis demonstrated that NMD treatment significantly decreased mRNA level of telomerase. Conclusion: These data suggest that NMD inhibit MNU-induced RD in rats. The expressions of TGF-β, telomerase and GSH contents might partially contribute to its protective effects on MNU-induced RD.
Keywords: Nimodipine, N-methyl-N-nitrosourea, retinal degeneration
|How to cite this article:|
Wang D, Li Y, Wang Z, Sun Gy, Zhang Qh. Nimodipine rescues N-methyl-N-nitrosourea-induced retinal degeneration in rats. Phcog Mag 2013;9:149-54
|How to cite this URL:|
Wang D, Li Y, Wang Z, Sun Gy, Zhang Qh. Nimodipine rescues N-methyl-N-nitrosourea-induced retinal degeneration in rats. Phcog Mag [serial online] 2013 [cited 2022 Jan 21];9:149-54. Available from: http://www.phcog.com/text.asp?2013/9/34/149/111276
| Introduction|| |
Retinitis pigmentosa (RP) refers to a heterologous group of inherited human disorders which caused primary retinal degeneration and are characterized by loss of photoreceptor cells via apoptosis.  The effective medicines are in various stages of development, no drugs are actually available to treat people with RP.
In recent years, there has been an upsurge of interest in unraveling the roles of Ca 2+ antagonists about the pathophysiology of different kinds of human diseases including neurodegenerative diseases, for example, retinal degeneration (RD). ,, Nimodipine (NMD) is a dihydropyridine calcium channel antagonist, which has been shown to dilate cerebral arterioles and increase cerebral blood flow in animals and humans.  Several studies in vitro and in vivo have demonstrated that NMD could protect retinal neurons from ischemic injury and was significantly effective vasodilators in human and pig retinal arterioles. , Several researchers reported that NMD had beneficial effect in visual field tests, color vision tests and contrast sensitivity, , and it has been shown to improve ocular hemodynamics and increase visual field in patients with normal-pressure glaucoma and primary open angle glaucoma. ,, In vitro, NMD has a direct neuroprotective effect against retinal ganglion cell damage related to hypoxia.  All these show that NMD is potentially useful for ophthalmic treatment. However, the effect of NMD is unknown on retinal degenerative diseases.
Herrold (1967) was the first to report RD in Syrian golden hamsters after systemic administration of the alkylating agent N-methyl-N-nitrosourea (MNU). A single systemic administration of MNU in rats leads to apoptosis and photoreceptor cell loss over approximately 7 days because it restricted deoxyribonucleic acid (DNA) methylation adduct formation in photoreceptor nuclei.  In previous studies, a dose of 60 mg/kg MNU was considered optimal to induce maximum damage in rat retinas.  MNU-induced photoreceptor cell death was attributed to the restriction of DNA adduct formation to photoreceptor cell nuclei leading to apoptosis.  Reactive oxygen species (ROS) play an important role in apoptosis induction under pathologic conditions,  which was related to cellular redox imbalance, as indicated by the depletion of glutathione (GSH), an essential regulator that maintains normal cellular redox status. ,, MNU also causes a decrease in reduced GSH, which effectively scavenges free radicals and other ROS. ,
The transforming growth factor-b (TGF-β) family that participates in a number of biological events such as proliferation, differentiation, apoptosis, and cell death, plays physiologic roles during embryonic development and tissue homeostasis in the adult. , Previous studies reported that TGF-β decreased the intracellular GSH content in various cells, and GSH reduces TGF-β-stimulated ROS signal regulation. ,
In addition, MNU has been implicated in various cancer models. A high expression level of telomerase is found within the germ line, embryonic stem cells, and cancer cells. According to these, we adopted the animal model of MNU-induced RD to assess the protective effect of NMD on morphology with electron microscopy, and the present work was to analyze whether resistance to MNU-induced damage might be due to the changes of GSH, TGF-β, and telomerase in retina.
| Materials and Methods|| |
Chemical and dose formulation
MNU (Sigma,USA) was kept at −20°C in the dark, it was dissolved in phosphate-buffered saline (PBS) just before use. NMD was purchased from Shandong Fangming Pharmaceutical Group Co., Ltd, China. GSH and TGF-β test Kits were purchased from Nanjing Jian cheng Bioengineering Institute, China. All other chemicals were purchased from commercial sources.
Animals and procedures
Six-week-old female Sprague-Dawley rats were purchased from the animal facility at the China Medical University, P. R. China. Animal experiments were performed in accordance with the Association for Research in Vision and Ophthalmology (ARVO) Statement for the use of animals in ophthalmic and vision research, and the study was approved by the local Medical Ethics Committee. Rats were reared under standard laboratory conditions (22 ± 2°C, 60% ± 10% relative humidity and a 12-h light-dark cycle) and had free access to food and water throughout the experiment.
Rats were randomly divided into three groups, including control group (NC group), MNU-treated group (MNU group), and NMD-treated group (NMD group). In the NMD group, rats received a single intraperitoneal (i.p.) injection of 60 mg/kg MNU, followed immediately by once daily i.p. of 2 mg/kg NMD for 5 days. In the MNU group, after a single i.p. of MNU injection, PBS (10 ml/kg, once a day) was administrated instead of NMD for 5 days. Rats in the NC group were injected with a corresponding bolus of PBS. The animals were sacrificed at 5 days after MNU treatment, rat eyes were enucleated to use for electron microscopy assay, reverse transcriptase polymerase chain reaction (RT-PCR) assay, determination of GSH and TGF-β.
Light microscopy assay
The eyes were fixed in 4% paraformaldehyde (PFA) for 24 h. Eyes were enucleated, a portion of cornea and lens were removed and the remaining eye cups containing the retinas were placed in 4% PFA overnight, the samples were incubated in 50% ethanol for 1 h, routinely dehydrated and embedded, and sagittal sections (4 ΅m thick) were cut near the optic nerve head. The slices were dewaxed, stained with hematoxylin and eosin (HE) for histological examination. To determine retinal damage, HE sections were examined under the optical microscopy (OLYMPUS, BX60 Japan) at 100-fold magnification.
Electron microscopy assay
A part of eyes reserved for electromicroscopy assay was kept in 2.5% glutaraldehyde overnight at 4°C, then the cornea and lens were removed and the remaining eye cups containing the retinas were placed in 2.5% glutaraldehyde overnight at 4°C. The samples were postfixed in 2% osmium solution for 20 min, then dehydrated and embedded in epon, and polymerased at 60°C. Thin sections (50 nm thick) stained with uranyl acetate and lead citrate were examined using a electron microscope (JEM-100CXII, Japan).
Determination of GSH content
A part of retinas were lysed directly on ice in 1 ml of PBS, after centrifugation, the supernatants were transferred to new tubes to examine TGF-β and GSH. The content of GSH was determined using the commercially available diagnostic kits and was measured by the method of Moron et al. 
ELISA analysis of TGF-β
The level of TGF-β was quantitated by a modification of a double ligand enzyme-linked immunosorbent assay (ELISA) method as previously described. 
RT-PCR analysis of telomerase
Total RNA from retinas was isolated using reagent Trizol (Gibco, Inc., Grand Island, NY) according to manufacturer's instructions.  Ribonucleic acid (RNA) was quantitated by measuring the OD260 and reverse transcribed into a single-stranded complementary deoxyribonucleic acid (cDNA) with the RevertAid H Minus First Strand cDNA Synthesis Kit, K1632 (Fermentas AB, Vilnius, Lithuania). cDNA was amplified for 25 cycles so that the PCR product remained in the linear range. PCR (Golden DNA Polymerase, KT221, Tiangen, China) was performed with gene-specific primers for β-actin, telomerase gene [Table 1]. β-actin was used as an internal control to confirm mRNA integrity. The identity of all PCR products was confirmed by comparison with the correct size based on the known length of the DNA sequence on 1% agarose gel stained by ethidium bromide. The optical density of the bands was analyzed on the GeneSnap system (Syngene, Synoptics Ltd. Frederick, MD).
Values are expressed as mean ± standard error. One-way analysis of variance (ANOVA) was used followed by Fisher's least-significant difference (LSD) for the homogeneity testing of variance (Levene's test), and the data were analyzed by Dunnett's T3 for the heteroschedasticity of variance test. P < 0.05 was considered statistically significant. All statistical procedures were performed using SPSS 13.0 software for Windows (SPSS Inc., USA).
| Results|| |
Morphological observation of NMD on MNU-treated rats
Histological observations showed that i.p. administration of 60 mg/kg/day MNU caused the severe degeneration in the outer nuclear layer at 5 days after MNU injection [Figure 1]. At the same time, the number of surviving photoreceptor cells in the NMD group was significantly increased at 5 days after MNU. At the ultrastructural level [Figure 2], electron microscopy showed that morphology of photoreceptor cell was normal in the NC group, whereas vacuoles and fusion of mitochondrion were more numerously seen and heterochromatin are lost in the MNU group. Electron microscopic analysis disclosed that photoreceptor cells were less deteriorated in the NMD group than in the MNU group. At 5 days after MNU injection, 2 mg/kg NMD partially protected against MNU-induced retinal damage. These observations suggest that NMD has a beneficial effect on MNU-induced RD.
|Figure 1: Effects of NMD on the retinal histological damage after MNU treatment in rats. Representative photographs of retinal sections stained with HE (H and E, each ×100): NC group, the normal outer nuclear layer; MNU group, the outer nuclear layer became thinned compared with NC group; NMD group, the outer nuclear layer became thicker compared with MNU group. Between arrowheads indicate the outer nuclear layer|
Click here to view
|Figure 2: Effects of NMD on photoreceptor cells after MNU treatment at the ultrastructural level in rats. NC group, the normal photoreceptor cell; MNU group, the apparent vacuoles and fusion of photoreceptor cell mitochondrion, and heterochromatin was lost; NMD group, the less deterioration of photoreceptor cell. Asterisk (*), photoreceptor cell nucleus; arrow, mitochondrion (each ×4000)|
Click here to view
The effect of NMD on GSH content induced by MNU
The content of GSH was substantially decreased in MNU group compared with the NC group. Although the level of GSH in the NMD group was significantly different from that of the NC group, it was also significantly different from that of the MNU group (partial protection) [Figure 3].
|Figure 3: Effects of NMD on GSH level in MNU-induced RD. After MNU treatment, the GSH level showed reductions. In rats receiving NMD treatment, the GSH level was significantly higher than those rats in the MNU group and lower than in the NC group. aP < 0.05, ##P < 0.01, compared with the NC group, *P < 0.05, compared with the MNU group|
Click here to view
The effect of NMD on TGF-β induced by MNU
As shown in [Figure 4], the level of TGF-β was up-regulated in the MNU group compared with the NC group. Treatment with NMD decreased the expression of TGF-β in MNU-induced RD.
|Figure 4: Liaoning effects of NMD on the level of TGF-âin MNU-induced RD. The retinal supernatants were assayed for TGF-âwith ELISA. After MNU treatment, the level of TGF-âshowed increase. In rats receiving NMD treatment, the level of TGF-âwas significantly lower than those rats in the MNU group. ##P < 0.01 compared with the NC group, *P < 0.05 compared with the MNU group. There is no significant difference between NC and NMD group|
Click here to view
The effect of NMD on telomerase induced by MNU
RT-PCR result of telomerase mRNA expression is shown in [Figure 5]a, and quantitative data are summarized in [Figure 5]b. Telomerase upregulated significantly in MNU group compared with the NC group. In the NMD group, telomerase was significantly lower than in the MNU group at 5 days.
|Figure 5: Effects of NMD on MNU-induced mRNA expression of telomerase in rat retina measured by RT-PCR, (a) DNA strips show expression levels of telomerase on agarose gel electrophoresis, (b) Effects of NMD on MNU-induced mRNA expression of telomerase in rat retina. #P < 0.05 versus NC group, *P < 0.05 versus MNU group. There is no significant difference between NC and NMD groups|
Click here to view
| Discussion|| |
NMD, an L-type calcium channel antagonist, has been mainly used in treatment of cardiovascular-related diseases, including angina pectoris, cardiac arrhythmia, and hypertension. NMD has been found to be beneficial in many central nervous system (CNS) disorders. The clinical studies demonstrated a favorable effect of NMD on the severity of neurological deficits caused by cerebral vasospasm following subarachnoid hemorrhage. , In the present study, systemic administration of NMD morphologically demonstrated a beneficial effect on RD caused by MNU. These results suggest that NMD has a protective effect against MNU-induced RD.
GSH, as a small molecule of radical scavenge, can act either as a nucleophile with the formation of conjugates or as a reducing agent to protect of cellular macromolecules, in which reaction, it is oxidized to its oxidized glutathione (GSSG). It has been reported that that GSH depletion causes increased secretion of vascular endothelial growth factor A (VEGF-A) in retinal pigment epithelium (RPE) and cellular redox status plays an important role in VEGF regulation in RPE cells.  In our study, we have found that neovascularization in retina was induced by a single i.p. injection of MNU in 3-4 weeks time period (data not shown). Viviane et al. confirm that NMD acts positively on lipid peroxidation.  In this present study, NMD treatment can increase the activity of GSH, thereby suggesting that this drug acts positively as a protective antioxidant.
TGF-β, a multifunctional cytokine, regulates cell proliferation, differentiation, and extracellular matrix synthesis. For ophthalmic study, the roles of TGF-β in retinal fibrosis, in proliferative retinal disorders and in macular degeneration are well documented. , Previous studies indicated that TGF-β and GSH mutual inhibit in hepatic stellate cells and murine embryonic fibroblasts. , In this study, MNU treatment can decrease the level of GSH, and TGF-β was expressed higher in the MNU group compared with the NC group. TGF-β was expressed lower in the NMD group compared with the MNU group. For the above reasons, we speculate that GSH depletion may be induced by TGF-β mediate and TGF-β might be involved in the effect of NMD on MNU-induced RD. The relation between GSH and TGF-β in retina still need to be further studied.
Telomerase is an enzyme that adds a six-base DNA repeat sequence (TTAGGG) to chromosome ends and thereby prevents their shortening during successive rounds of mitosis. ,, The presence of telomerase activity in retina indicates that a fully functional form of telomerase can be found in the retina.  The expression of telomerase activity in retina implies other functions, such as regulation of cell cycle progression and maintenance of retinal cell phenotypes. , It has been reported that there are significant changes of gene expression in the early stage of MNU-induced RD.  In this present study, RT-PCR analyses revealed that telomerase mRNA levels decreased at 5 days after NMD injection. These results indicate that NMD treatment may modulate expression of telomerase to inhibit MNU-induced damage.
In conclusion, this study suggest that down-regulation of TGF-β and telomerase mRNA may play an important role in the protective effect of NMD against the MNU-induced damage, and it is also shown that the NMD protective effect can be responsible for influencing the content of GSH.
| Acknowledgments|| |
This work was supported by China Medical University. All of the authors agree to the submission of this paper and no competing financial interests exist.
| References|| |
|1.||van Soest S, Westerveld A, de Jong PT, Bleeker-Wagemakers EM, Bergen AA. Retinitis pigmentosa: defined from a molecular point of view. Surv Ophthalmol 1999;43:321-34. |
|2.||Takeuchi K, Nakazawa M, Mizukoshi S. Systemic administration of nilvadipine delays photoreceptor degeneration of heterozygous retinal degeneration slow (rds) mouse. Exp Eye Res 2008;86:60-9. |
|3.||Takano Y, Ohguro H, Dezawa M, Ishikawa H, Yamazaki H, Ohguro I, et al. Study of drug effects of calcium channel blockers on retinal degeneration of rd mouse. Biochem Biophys Res Commun 2004;313:1015-22. |
|4.||Sato M, Ohguro H, Ohguro I, Mamiya K, Takano Y, Yamazaki H, et al. Study of pharmacological effects of nilvadipine on RCS rat retinal degeneration by microarray analysis. Biochem Biophys Res Commun 2003;306:826-31. |
|5.||Langley MS, Sorkin EM. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in cerebrovascular disease. Drugs 1989;37:669-99. |
|6.||Crosson CE, Willis JA, Potter DE. Effect of the calcium antagonist, nifedipine, on ischemic retinal dysfunction. J Ocul Pharmacol 1990;6:293-9. |
|7.||Yu DY, Su EN, Cringle SJ, Alder VA, Yu PK, Desantis L. Effect of betaxolol, timolol and nimodipine on human and pig retinal arterioles. Exp Eye Res 1998;67:73-81. |
|8.||Piltz JR, Bose S, Lanchoney D. The effect of nimodipine, a centrally active calcium antagonist, on visual function and muscular blood flow in patients with normal-tension glaucoma and control subjects. J Glaucoma 1998;7:336-42. |
|9.||Boehm AG, Breidenbach KA, Pillunat LE, Bernd AS, Mueller MF, Koeller AU. Visual function and perfusion of the optic nerve head after application of centrally acting calcium-channel blockers. Graefes Arch Clin Exp Ophthalmol 2003;241:34-8. |
|10.||Flammer J, Orgul S, Costa VP, Orzalesi N, Krieglstein GK, Serra LM, et al. The impact of ocular blood flow in glaucoma. Prog Retin Eye Res 2002;21:359-93. |
|11.||Koseki N, Araie M, Yamagami J, Shirato S, Yamamoto S. Effects of oral brovincamine on visual field damage in patients with normal-tension glaucoma with low-normal intraocular pressure. J Glaucoma 1999;8:117-23. |
|12.||Flammer J. Therapeutic aspects of normal-tension glaucoma. Curr Opin Ophthalmol 1993;4:58-64. |
|13.||Niwa Y, Yamamoto T, Harris A, Kagemann L, Kawakami H, Kitazawa Y. Relationship between the effect of carbon dioxide inhalation or nilvadipine on orbital blood flow in normal-tension glaucoma. J Glaucoma 2000;9:262-7. |
|14.||Yoshizawa K, Nambu H, Yang J, Oishi Y, Senzaki H, Shikata N, et al. Mechanisms of photoreceptor cell apoptosis induced by N-methyl-N-nitrosourea in Sprague-Dawley rats. Lab Invest 1999;79:1359-67. |
|15.||Miki K, Uehara N, Shikata N, Matsumura M, Tsubura A. Poly (ADP-ribose) polymerase inhibitor 3-aminobenzamide rescues N-methyl-N-nitrosourea-induced photoreceptor cell apoptosis in Sprague-Dawley rats through preservation of nuclear factor-kB activity. Exp Eye Res 2007;84:285-92. |
|16.||Valko M, Leibfritz D, Moncol J, Cronin MT, Mazur M, Telser J. Free radicals and antioxidants in normal physiological functions and human disease. Int J Biochem Cell Biol 2007;39:44-84. |
|17.||White AC, Das SK, Fanburg BL. Reduction of glutathione is associated with growth restriction and enlargement of bovine pulmonary artery endothelial cells produced by transforming growth factorb1. Am J Respir Cell Mol Biol 1992;6:364-8. |
|18.||Arsalane K, Dubois CM, Muanza T, Begin R, Boudreau F, Asselin C, et al. Transforming growth factor- beta 1 is a potent inhibitor of glutathione synthesis in the lung epithelial cell line A549: Transcriptional effect on the GSH rate-limiting enzyme g-glutamylcysteine synthetase. Am J Respir Cell Mol Biol 1997;17:599-607. |
|19.||Sanchez A, Alvarez AM, Benito M, Fabregat I. Cycloheximide prevents apoptosis, reactive oxygen species production, and glutathione depletion induced by transforming growth factor b in fetal rat hepatocytes in primary culture. Hepatology 1997;26:935-43. |
|20.||Cengiz M, Hacihanefioglu S, Cenani A. Glutathione and related enzymes in rat liver treated with methyl nitrosourea. J Basic Clin Physiol Pharmacol 1996;7:341-5. |
|21.||Wu G, Fang YZ, Yang S, Lupton JR, Turner ND. Glutathione metabolism and its implications for health. J Nutr 2004;134:489-92. |
|22.||Heldin CH, Landstrom M, Moustakas A. Mechanism of TGF- beta signalling to growth arrest, apoptosis, and epithelial-mesenchymal transition. Curr Opin Cell Biol 2009;21:166-76. |
|23.||Attisano L, Wrana JL. Signal transduction by the TGF- beta superfamily. Science 2002;296:1646-7. |
|24.||Liu RM, Liu Y, Forman HJ, Olman M, Tarpey MM. Glutathione regulates transforming growth factor-b-stimulated collagen production in fibroblasts. Am J Physiol Lung Cell Mol Physiol 2004;286:L121-8. |
|25.||Vayalil PK, Iles KE, Choi J, Yi AK, Postlethwait EM, Liu RM. Glutathione suppresses TGF-β-induced PAI-1 expression by inhibiting p38 and JNK MAPK and the binding of AP-1, SP-1, and Smad to the PAI-1 promoter. Am J Physiol Lung Cell Mol Physiol 2007;293:L1281-92. |
|26.||Moron MS, Depierre JW, Mannervik B. Levels of glutathione, glutathione reductase and glutathione S-transferase activities in rat lung and liver. Biochim Biophys Acta 1979;582:67-78. |
|27.||Bian ZM, Elner SG, Yoshida A, Elner VM. Differential involvement of phosphoinositide 3-kinase/Akt in human RPE MCP-1 and IL-8 expression. Invest Ophthalmol Vis Sci 2004;45:1887-96. |
|28.||Gao Y, Deng XG, Sun QN, Zhong ZQ. Ganoderma spore lipid inhibits N-methyl-N-nitrosourea-induced retinal photoreceptor apoptosis in vivo. Exp Eye Res 2010;90:397-404. |
|29.||Murray GD, Teasdale GM, Schmitz H. Nimodipine in traumatic subarachnoid haemorrhage: A re-analysis of the HIT I and HIT II trials. Acta Neurochir (Wien) 1996;138:1163-7. |
|30.||Vergouwen MD, Vermeulen M, Roos YB. Effect of nimodipine on outcome in patients with traumatic subarachnoid haemorrhage: A systematic review. Lancet Neurol 2006;5:1029-32. |
|31.||Sreekumar PG, Kannan R, de Silva AT, Burton R, Ryan SJ, Hinton DR. Thiol regulation of vascular endothelial growth factor-A and its receptors in human retinal pigment epithelial cells. Biochem Biophys Res Commun 2006;346:1200-6. |
|32.||Nascimento VS, D'alva MS, Oliveira AA, Freitas RM, Vasconcelos SM, Sousa FC, et al. Antioxidant effect of nimodipine in young rats after pilocarpine-induced seizures. Pharmacol Biochem Behav 2005;82:11-6. |
|33.||Wiedemann P. Growth factors in retinal diseases: Proliferative vitreoretinopathy, proliferative diabetic retinopathy, and retinal degeneration. Surv Ophthalmol 1992;36:373-84. |
|34.||Honjo Y, Nagineni CN, Larsson J, Nandula SR, Hooks JJ, Chan CC, et al. Neuron-specific TGF-β signaling deficiency results in retinal detachment and cataracts in mice. Biochem Biophys Res Commun 2007;352:418-22. |
|35.||Min XJ, Zhou QJ, Liu T, Yin HM, Dong XG, Xie LX. Expression of mouse telomerase reverse transcription in a mouse model of oxygen-induced retinopathy. Zhonghua Yan Ke Za Zhi 2009;45:199-205. |
|36.||Lau BW, Wong AO, Tsao GS, So KF, Yip HK. Molecular cloning and characterization of the zebrafish (Danio rerio) telomerase catalytic subunit (telomerase reverse transcriptase, TERT). J Mol Neurosci 2008;34:63-75. |
|37.||Lau BW, Tsao GS, So KF, Yip HK. Expression of telomerase reverse transcriptase in adult goldfish retina. J Mol Neurosci 2007;32:160-7. |
|38.||Yang L, Li D, Chen JM, Yang JN, Xue LP, Hu SX, et al. Microarray expression analysis of the early N-methy-N-nitrosourea-induced retinal degeneration in rat. Neurosci Lett 2007;418:38-43. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
|This article has been cited by|
||Rebaudioside A/TPGS mixed nanomicelles as promising nanocarriers for nimodipine ocular delivery
| ||Xuefei Li, Jingwang Fang, Meng Xin, Qiqi Li, Jun Wang, Hui Yang, Xianggen Wu |
| ||Drug Delivery and Translational Research. 2021; 11(3): 1119 |
|[Pubmed] | [DOI]|
||A role of Heat Shock Protein 70 in Photoreceptor Cell Death: Potential as a Novel Therapeutic Target in Retinal Degeneration
| ||Ayako Furukawa,Yoshiki Koriyama |
| ||CNS Neuroscience & Therapeutics. 2016; 22(1): 7 |
|[Pubmed] | [DOI]|
||Suppression of <i>N</i>-Methyl-<i>N</i>-Nitrosourea-Induced Retinal Damage in Mice by Oligonol, an Oligomerized Polyphenol Formulation
| ||Jun Kisugi,Miwako Nasui,Koji Wakame,Jun Takanari,Masatoshi Yamazaki,Satoru Yui |
| ||Advances in Biological Chemistry. 2014; 04(02): 138 |
|[Pubmed] | [DOI]|
||nimodipine rescues n-methyl-n-nitrosourea-induced retinal degeneration in rats
| ||wang, dan and li, yan and wang, zhuo and sun, gui-yuan and zhang, qiu-hua |
| ||pharmacognosy magazine. 2013; 9(34): 149 |